Electrician&#39;s tool



June -27, 1939. N GlzzARE- LU 2,163,676

ELEGTRICIANS Toon Filed June-1, 1937 INVENTOR.

ATTORNEYS.

Patented June 227, 1939 UNiTEo "STATES ATENT OFFICE.

4 Claims.

This invention relates to an electricians tool; and has for one of its objects the provision .of a combined screw driver and tester which will be of such a character that when a live wire or ;.circuit is contacted. by thetip or shank of a screw driver a signal lamp will glow in the body of the screw driver even though there be no. cornplete electrical circuit through the lamp.

Another object of the invention is the provimsion of an arrangement whereby thetester may be optionally used in such a way that a complete circuit may be passed through the Asignal lamp by attaching some lead at a convenient location upon the body of the screw driver.

Another object of the invention is the simplification of the `assembled parts and their manner of assembly so that the device may bemade inexpensively and placed on the market ata comparatively low cost.

Another object of the, invention is the easy assemblyv and detachment of the parts to provide for easy replacement of the signal lamp by a fresh one should the original lamp fail to function.

With these and other objects in view, the invention consists of certain novel features of construction, as will be more fully described, and particularly pointed out in the appended claims.

In the accompanying drawing:

Fig. 1 is an elevation of the screw driverrwith the body thereof in section;

Fig. 2 is an elevation of the handle alone;

Fig. 3 is a section of the body alone with the signal lamp removed;

35 Fig. 4 is an elevation of the screw driver shank; Fig. 5 is a sectional view on line 5-5 of Fig. 1; Fig. 6 is a sectional view of a modified form ol' body which may be used in place of that shown in Figs. 1 and 3.

A screw driver has been found to be extremely useful and perhaps one of the most used instruments or tools of electricians. Testing devices are also used but usually are in some separate instrument and require the positioning of the ends of two leads in order that a circuit may be completed through the signal. I have found that a neon lamp will glow even if one of its terminals are connected to a live circuit without it being necessary to pass a current completely through the lamp; and in order to utilize this characteristic of a neon lamp and also to locate the neon lamp in an extremely convenient place, I have so formulated a screw driver that the neon lamp will be in the body thereof with the 55 blade or shank of the screw driver connected to one terminal of the neon signal lamp so that if this blade touches a live circuit the neon lamp will glow. I have also arranged 4in addition a terminal which may be optionally used where a bright glow in the lamp is desired, or for other uses, to place the neon lamp completely in circuit; and the following is a more detailed description of the present embodiment of this invention, illustrating the preferred means by which these advantageous results may be accomplished:

With reference to the drawing, III designates the hollow cylindrical tubular body of the screw driver which, as shown in Figs. l and 2, is made of insulating material such as fiber or some molded or plastic insulating composition such as Bakelite. The tube is provided with internal threads II at its upper end and I2 at its lower end and is also provided with an opening I3 of an elongated shape, as lshown in Fig. 3, at a convenient location along the length of the body.

A handle designated generally I4 is provided with a threaded stud portion I5 to iit into the threads I I of the body I0, while a pin I6 may extend through the diametrically opposite openings I'I and I8 in the body I0 and the hole I9 in the threaded portion I5 of the handle to lock the handle in position V'against turning. The end of the pin I6 is threaded as at 2|] to fit into the threaded hole I8 to hold the same in position.

A shank 2| has a screw driver blade 22 With an enlarged head portion 23 which is threaded to fit into the threads I2 at the lower end of the body where the same is held in place by a set screw 24 having a manipulating slot 25. In the head 23 there is located threaded opening 26 for the reception of a binding screw 2l.

A cradle 28 has its outer surface 29 shaped to fit the inner surface of the body and isI recessed as at 30 to receive the neon signal lamp or bulb 3| which has terminals 32 and 33 extending therefrom. The recess is of such a shape as to snugly fit the neon lamp and hold it in position against the inner wall of the tube I0 in a location opposite the opening I3 so that the same may be viewed from the outside of the instrument. The end portion of the cradle as at 34 is shaped to prevent the tube from moving longitudinally of the cradle, while the cradle itself is held in position by the binding screw 35 passing through the wall of the tube I0 and into a threaded opening in the cradle 28.

The terminal 32 is connected by a suitable lead 36 to the binding screw 21 thus electrically connecting the shank 2| with the signal lamp 3I. 'I'he other terminal 33 of the neon signal lamp is 55 connected by lead 31 to the tubular rivet 38 with a binding post 39 threaded thereinto. This binding post has an insulating head 40 so that should one contact the post no shock will be obtained.

In use, this instrument of course may be used as an ordinary screw Idriver whenever and. whereever desired. In addition, the screw driver may be used in determining a live circuit by merely touching the shank portion 2l or its blade 22 to a live circuit whereupon the neon lamp will glow. Other uses are that the shank 2| may be grounded and a lead secured to the binding post 39 which may be manipulated among diierent wires to search for a live circuit whereupon a greater glow will be had in the neon lamp because of the current passing completely through the lamp, by reason of itsI being put into a circuit than were but one terminal of the lamp connected to an electric current.

In some cases instead of using a body l sufficiently thick to provide threads therein I may provide a thinner body 42 `and a metal ferrule 3 having threads- 44 located in one end of the body and rolled over as at l5 to secure it in position, the same. arrangement being provided at the lower end of the tube.

The foregoing description is directed solely towards the construction illustrated, but I desire it to be understood that I reserve the privilege of resorting to all the mechanical changes to which the device is susceptible, the invention being deflned and limited only by the terms of the aplpended claims.

I claim:

1. In a combination screwv driver and tester, aV

40 said cradle, said cradle having a concave surface engaging an end portion of said neon lamp, a metal vshank at one end of the body, and means to electrically connect said shank and lamp.

2. In a combination screw driver and tester, a hollow body having an opening, a cradle in the body positioned to engage the sides of a neon signal lamp and support the same in position to be viewed through said opening, said cradle having a concave surface engaging an end portion of'said. neon lamp, a neon lamp in said cradle having two terminals, a metal shank at one end of the body, means to electrically connect said shank to one of said terminals, a binding post on said body, and means to electrically connect the binding post to the other terminal.

3. In a combination screw driver and tester, a hollow body having an opening, a cradle in the body positioned to engage the sides or" a neon signal lamp and support the same in position to be viewed through said opening, said cradle having a concave surface engaging an end portion of said neon lamp, means to removably attach saidy cradle to said body, a neon lamp in said cradle, a metal shank at one end oi' the body, and means to` electrically connect said shank and lamp.

4. In a combination screw driver and tester, a hollow body having an opening therein, a neon lamp in said body having two terminals, a cradle inthe body positioned to engage the sides of said lamp and support the same, said cradle having a surface engaging an end portion of said neon lamp, ametal shank at one end of the body, means to electrically connect said shank to one of said terminals, a binding post on the outer surface of said body and havingV the exposed surface electrically insulated, and means electrically connectingfthe binding post to the other terminal of said lamp. j

. NICKOLAS GIZZARELLI. 

